1. Field of the Invention
This invention relates to vehicle traction apparatus of the type including an endless concavo-convex band or loop wheel and more particularly to apparatus for supporting the band on a vehicle to improve its load supporting characteristics and to improve its longevity.
2. Description of the Prior Art
Italian Pat. No. 438,805 and U.S. Pat. No. 2,055,932 disclose structures that incorporate an endless band of concavo-convex configuration for use as a traction member on a vehicle. Because neither of the prior art structures includes mechanism for supporting the side edges of the endless band their load capabilities are extremely low and their longevity is poor.
Commonly owned U.S. patent application Ser. No. 867,428, filed Jan. 6, 1978 by Wolfgang Trautwein discloses an endless traction band and edge support structure therefor that is far superior to the systems disclosed in the references noted in the preceding paragraph. The band disclosed in the Trautwein application is retained in positive sprocket engagement by means of transversely extending stud bands having at opposite ends threaded studs which are installed coaxially with roller chain rollers disposed at opposite side edges of the endless band. Although such system has good load supporting characteristics, its longevity is reduced because of the flexure of the bands and studs that are experienced during operation.